This invention relates a data structure (or a recording format) capable of recording one or more types of information, including audio information, among video (movie) information, still picture (still image) information, and audio (sound) information and performing common management of these types of information, an information medium for recording information using the data structure, and a method of recording information based on the data structure onto an information medium.
(Prior Art)
DVD videos (for playback only), optical discs on which video information has been recorded by a video compression method complying with the MPEG 2 standard, have already been commercialized and rapidly been popularized. On the other hand, recordable/reproducible DVDs which enable the user to digital-record analog video information have begun to appear on the market. The recordable/reproducible DVD is also called RTR (real-time recording recordable/reproducible DVD). The standardization of streamers that record digital TV broadcast reception video information (digital bit streams) is also in progress. In the format structure conforming to the standard that allows the user to record video information, playback units are represented in cells as in the format of the DVD video disc and the relationship between the individual cells is included in PGC (program chain) control information. Presently, MDs (minidiscs) are available on the market as user-oriented digital audio recording mediums.
(Subjects)
Since the RTR (recordable/reproducible DVD) disc differs from the MD in the disc size and the data format in recording, the MD recording data cannot be recorded directly in the RTR (recordable/reproducible DVD) format. Moreover, in the RTR (recordable/reproducible DVD) standard, audio information cannot be recorded on an information medium independently. Thus, presently, there is no method of recording audio information together with video information and/or still picture information on a single information medium and reproducing those types of information in a mixed manner in an arbitrary order.
(Objects)
An object of the present invention is to provide a data structure (format structure) which enables not only video information, still picture information and/or audio information to be mixed with each other and recorded on the same information medium but also any area in each of the video information, still picture information, and audio information to be reproduced in an arbitrary order.
One other object of the present invention is to provide an information medium on which information is recorded using the data structure (format structure).
Still one other object of the present invention is to provide a method of recording information based on the data structure (format structure) on an information medium.
To accomplish the object, a data structure (or a format structure) according to the present invention is as follows:
1. Audio information is recorded on an information medium in a format obtained by expanding the RTR (recordable/reproducible DVD) standard.
2. For management information about each piece of information recorded on the information medium, an xe2x80x9caudio information cellxe2x80x9d is defined as a playback unit even for audio information as in the RTR standard. To a PGC (program chain) higher in level than the cell, xe2x80x9cplayback sequencexe2x80x9d information about the relationship between other video information (movie cells) and/or still picture information (still picture cells) is given.
To accomplish the one other object, an information medium according to the present invention has an audio information recording area (RTR_STO.VRO/RTR_STA.VRO/RTR_AUD.VRO/STREAM.VRO) in which audio information is recorded and a management area (RTR.IFO/STREAM.IFO) in which management information about the recording area is recorded. On the information medium, other information (including video information and still picture information) as well as audio information can be recorded. In the management area (RTR.IFO/STREAM.IFO), management information about other information (including video information and still picture information) as well as audio information can be recorded. Moreover, in the management area (RTR.IFO/STREAM.IFO), information about the relationship between all the pieces of audio information in reproducing or information (PGCI) about the relationship between the audio information and information (including video information and still picture information) other than the audio information can be recorded.
To achieve the still one other object, a recording method according to the present invention comprises a first recording process (step ST10) for recording one or more type of information including audio information onto the information medium and a second recording process (step ST12) for writing additionally management information about the recorded information onto the information medium or changing the management information.
In the second recording process (ST12), information (original PGC/user-defined PGC) about the relationship between the audio information and other recording information (video information and/or still picture information) in reproducing the audio information recorded on the information medium in the first recording process (ST10) is written additionally into the management area (RTR.IFO/STREAM.IFO) on the information medium or is changed and recorded in the management area.
To execute what have been described above, an embodiment of the present invention provides the following:
A. Cell type information is given to a piece of information corresponding to each cell. Pieces of identification information called xe2x80x9cmovie cell,xe2x80x9d xe2x80x9cstill picture cell,xe2x80x9d and xe2x80x9caudio cellxe2x80x9d are included in the cell type information. This makes it possible to discriminate between video information, still picture information, and audio information and mix these types of information with one another.
B. xe2x80x9cComposite cellxe2x80x9d information is further included in the cell type information, which provides a structure that makes it possible to reproduce specific (arbitrary) audio information, while reproducing specific (arbitrary) still picture information.
C. xe2x80x9cSilent cellxe2x80x9d information is added in the cell type information, which enable the user to set a silent period.
D. The audio information is provided with xe2x80x9ctime mapxe2x80x9d information as in the case of the video information. Use of the time map information makes it possible to make time search for the audio information at any time (at any playback time).
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.